The idea for the collaboration arose after Reed and Metallica shared the stage in 2009, at the Rock and Hall of Fame's 25th Anniversary concert in Madison Square Garden. Ever since, "we have been kicking around the idea of making a record together," the band said, adding that the album was recorded "over the last few months" at its home studio in San Francisco.

"In what would be lightning speed for a Metallica related project, we recorded ten songs during this time and while at this moment we're not exactly sure when you'll hear it, we're beyond excited to share with you that the recording sessions wrapped up last week."

In an interview with Rolling Stone, Reed describes the collaboration as "a marriage made in heaven," while Metallica drummer Lars Ulrich says the album is "90 percent" finished and plans for releasing it are not yet finalized, since neither the band nor Reed are currently signed to a record deal. "I don't think we've ever felt this free," he says. "There's nothing that's totally outside of the boundary for us, nothing that feels like 'Oh, what happens if we go there?' The strength of us is it feels like we cannot land on a wrong place."

Two tracks have also been revealed: "Pumping Blood," a seven-minute metal song cut in one take, and a Reed-fronted number entitled "Mistress Dread."